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            <h2 class="title" style="clear: both"><a id="dbset_errfile"></a>Db::set_errfile()</h2>
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      <pre class="programlisting">#include &lt;db_cxx.h&gt;

void Db::set_errfile(FILE *errfile); </pre>
      <p>
        When an error occurs in the Berkeley DB library,
        
         <span>
             an exception is thrown
         </span>
         or an error return value is returned by the interface.  In some cases,
         however, the <span class="bold"><strong>errno</strong></span> value may be
         insufficient to completely describe the cause of the error, especially
         during initial application debugging.
    </p>
      <p>
         The <a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a>  and
         <code class="methodname">Db::set_errfile()</code> methods are used to enhance the mechanism for
         reporting error messages to the application by setting a C library
         FILE * to be used for displaying additional Berkeley DB error
         messages.  In some cases, when an error occurs, Berkeley DB will
         output an additional error message to the specified file reference.
    </p>
      <p>
         Alternatively, you can use the
            <span>
                <a class="xref" href="envset_error_stream.html" title="DbEnv::set_error_stream()">DbEnv::set_error_stream()</a>
                and
                <a class="xref" href="dbset_error_stream.html" title="Db::set_error_stream()">Db::set_error_stream()</a>
                methods to display the additional messages via an output stream, or the
            </span>

         <a class="xref" href="envset_errcall.html" title="DbEnv::set_errcall()">DbEnv::set_errcall()</a>  or
         <a class="xref" href="dbset_errcall.html" title="Db::set_errcall()">Db::set_errcall()</a>
         methods to capture the additional error information in a way that does
         not use C library FILE *'s. 
         <span>You should not mix these approaches.</span>
    </p>
      <p>
         The error message will consist of the prefix string and a colon
         ("<span class="bold"><strong>:</strong></span>") (if a prefix string was
         previously specified using 
         <a class="xref" href="dbset_errpfx.html" title="Db::set_errpfx()">Db::set_errpfx()</a>  or 
         <a class="xref" href="envset_errpfx.html" title="DbEnv::set_errpfx()">DbEnv::set_errpfx()</a> ), an
         error string, and a trailing &lt;newline&gt; character.
    </p>
      <p>
         The default configuration when applications first create 
         <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a>  or 
         <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>  handles is as if the
         <a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a>  or
         <code class="methodname">Db::set_errfile()</code> methods were called with the standard error output
         (stderr) specified as the FILE * argument.  Applications wanting no
         output at all can turn off this default configuration by calling the
         <a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a>  or
         <code class="methodname">Db::set_errfile()</code> methods with NULL as the FILE * argument. 
         Additionally, explicitly configuring the error output channel using
         any of the following methods will also turn off this default output for the application:
     </p>
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            <p>
                <code class="methodname">Db::set_errfile()</code>
             </p>
          </li>
          <li>
            <p>
                <a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a>
             </p>
          </li>
          <li>
            <p>
                <a class="xref" href="envset_errcall.html" title="DbEnv::set_errcall()">DbEnv::set_errcall()</a>
             </p>
          </li>
          <li>
            <p>
                <a class="xref" href="dbset_errcall.html" title="Db::set_errcall()">Db::set_errcall()</a>
             </p>
          </li>
          <li>
            <p>
                <a class="xref" href="envset_error_stream.html" title="DbEnv::set_error_stream()">DbEnv::set_error_stream()</a>
             </p>
          </li>
          <li>
            <p>
                 <a class="xref" href="dbset_error_stream.html" title="Db::set_error_stream()">Db::set_error_stream()</a>
             </p>
          </li>
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      <p>
         This error logging enhancement does not slow performance or
         significantly increase application size, and may be run during normal
         operation as well as during application debugging.
    </p>
      <p>
         For <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a>  handles opened
         inside of Berkeley DB environments, calling the 
         <code class="methodname">Db::set_errfile()</code>
         method affects the entire environment and is equivalent to calling the
         <a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a> 
         method.
    </p>
      <p>
        When used on a database that was <span class="emphasis"><em>not</em></span> opened in
        an environment, the <code class="methodname">Db::set_errfile()</code>
        method configures operations performed using the specified 
        <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a> handle, not all operations
        performed on the underlying database.
    </p>
      <p>
         The <code class="methodname">Db::set_errfile()</code> method may be called at any time during the
         life of the application.
    </p>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp1381032"></a>Parameters</h3>
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          </div>
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        <div class="sect3" lang="en" xml:lang="en">
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            <div>
              <div>
                <h4 class="title"><a id="idp1360312"></a>errfile</h4>
              </div>
            </div>
          </div>
          <p>
                          The <span class="bold"><strong>errfile</strong></span> parameter is a C library
                          <code class="literal">FILE *</code> to be used for displaying additional Berkeley DB error
                          information.
                     </p>
        </div>
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      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp1726384"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
                <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a>  
            </p>
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      <div class="sect2" lang="en" xml:lang="en">
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              <h3 class="title"><a id="idp2025584"></a>See Also</h3>
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        <p>
                     <a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a> 
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